Contents

Description

Currently UBI and UBIFS seem to allocate a lot vmalloced LEB-sized buffers
on mount time. The reason for this is to "reserve" such memory and prevent
the big allocations from failing at a later point.

This heavily affects the memory footprint in systems using UBIFS.

A possible solution is to implement scatter-gather lists support in UBI
and UBIFS and replace the big (LEB-sized) vmallocations by smaller
allocations.

While this is a big effort and will only benefit UBIFS, it is expected that
it will help reduce the memory usage in such systems.

In addition, it has the added benefit of addressing another problem.
Some ARM platforms don't support DMA on vmalloc'ed buffers;
using scatter-gather lists the allocated will be quite smaller -O(page)-,
and it will be possible to allocate them on physically contiguous memory
(DMA capable).